Mask system

ABSTRACT

A shroud ( 1020 ) for a mask system includes a retaining portion structured to retain a frame ( 1040 ), a pair of upper headgear connectors ( 1024 ) each including an elongated arm ( 1026 ) and a slot ( 1027 ) at the free end of the arm adapted to receive a headgear strap, and a pair of lower headgear connectors ( 1025 ) each adapted to attach to a headgear strap. The retaining portion, the upper headgear connectors, and the lower headgear connectors are integrally formed as a one piece structure.

CROSS-REFERENCE TO APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/964,280, filed Aug. 12, 2013, pending, which is a continuation ofU.S. application Ser. No. 13/745,077, now U.S. Pat. No. 8,528,561, filedon Jan. 18, 2013, which is a continuation of U.S. application Ser. No.12/736,024, now U.S. Pat. No. 8,550,084, filed on Sep. 2, 2010, which isthe U.S. National Stage of PCT/AU2009/000241, filed Feb. 27, 2009, whichclaims benefit to U.S. Provisional Application Nos. 61/064,406, filedMar. 4, 2008, 61/071,893, filed May 23, 2008, and 61/136,617, filed Sep.19, 2008, each of which is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention relates to a mask system used for treatment, e.g.,of Sleep Disordered Breathing (SDB) with Continuous Positive AirwayPressure (CPAP) or Non-Invasive Positive Pressure Ventilation (NIPPV).

BACKGROUND OF THE INVENTION

Patient interfaces, such as a full-face or nasal mask systems, for usewith blowers and flow generators in the treatment of sleep disorderedbreathing (SDB), typically include a soft face-contacting portion, suchas a cushion, and a rigid or semi-rigid shell or frame. In use, theinterface is held in a sealing position by headgear so as to enable asupply of air at positive pressure (e.g., 2-30 cm H₂O) to be deliveredto the patient's airways.

One factor in the efficacy of therapy and compliance of patients withtherapy is the comfort and fit of the patient interface.

The present invention provides alternative arrangements of mask systemsto enhance the efficacy of therapy and compliance of patients withtherapy.

SUMMARY OF THE INVENTION

One aspect of the invention relates to a mask system provided without aforehead support adapted to engage the patient's forehead.

Another aspect of the invention relates to a mask system including aframe and a shroud removably connected to the frame and adapted toattach headgear.

Another aspect of the invention relates to a mask system including aframe defining a breathing chamber, a cushion provided to the frame andadapted to form a seal with the patient's face, and a shroud provided tothe frame. The shroud and the frame are co-molded with one another. Theframe is constructed of a first, relatively soft, elastomeric materialand the shroud is constructed of a second material that is more rigidthan the frame. At least a portion of the frame includes a concertinasection having a plurality of folds. Each of the folds has a side wallwith the side walls of the folds becoming progressively longer away fromthe patient's face.

Another aspect of the invention relates to a cushion module including aframe defining a breathing chamber and a cushion adapted to form a sealwith the patient's face. The frame and the cushion are co-molded withone another. The cushion is constructed of a first, relatively soft,elastomeric material and the frame is constructed of a second materialthat is more rigid than the cushion. At least a portion of the frameincludes a concertina section.

Another aspect of the invention relates to a method for constructing acushion module. The method includes molding a first part of the cushionmodule with a first, relatively soft, elastomeric material, co-molding asecond part of the cushion module to the first part with a secondmaterial that is more rigid than the first material, and molding atleast a portion of the second part to include a concertina section.

Another aspect of the invention relates to a shroud for a mask systemincluding a retaining portion structured to retain a frame, a pair ofupper headgear connectors each including an elongated arm and a slot atthe free end of the arm adapted to receive a headgear strap, and a pairof lower headgear connectors each adapted to attach to a headgear strap,wherein the retaining portion, the upper headgear connectors, and thelower headgear connectors are integrally formed as a one piecestructure.

Another aspect of the invention relates to a mask system including aframe defining a breathing chamber, a cushion provided to the frame andadapted to form a seal with the patient's face, a shroud provided to theframe and adapted to attach headgear, and an elbow provided to the frameand adapted to be connected to an air delivery tube that deliversbreathable gas to the patient. The shroud includes a retaining mechanismstructured to establish a positive connection between the shroud and theframe.

Another aspect of the invention relates to a mask system including aframe defining a breathing chamber and a cushion provided to the frame.The cushion includes a main body and a cushion, wherein the cushion isadapted to engage at least a portion of the patient's face. The cushionincludes a base wall connected to an undercushion layer and a membrane,wherein the membrane extends around the perimeter of the cushion andcontacts the patient's face. The undercushion layer is positionedunderneath the membrane and supports the membrane. The under cushionlayer provides differential support to the membrane at predeterminedregions of the face.

Another aspect of the invention relates to a mask assembly for use inmedical applications having a top and bottom ends defined by itsposition relative to a patient's face, wherein the mask assembly isconnected to a plurality of flexible straps, which are adapted to engagethe patient's head. The flexible straps engage at least two elongatedrigid arms integrally molded to a portion of the mask assembly, andwherein the elongated arms are molded to the mask assembly proximal tothe top end of the mask assembly.

Another aspect of the invention relates to a mask assembly for use inmedical applications including a main body connected to a cushionadapted to cover nose and/or mouth and wherein the mask assembly isattached by a force substantially perpendicular towards the face andwherein the force is approximately constant along the length of the maskand is balanced by a portion of the cushion engaging the patient'scheeks.

Another aspect of the invention relates to a cushion for use with amedical mask including an outer membrane layer adapted to sealablyengage a face and an undercushion layer adapted to support the membranelayer. The membrane or undercushion layer includes a surface positionedbetween the two layers adapted to allow the layers to slide against therespective surface.

Another aspect of the invention relates to a mask system including aframe defining a breathing chamber, a cushion provided to the frame andadapted to form a seal with the patient's face, and a releasable shroudadapted to engage a portion of the outer surface of the frame, whereinthe shroud is connected to straps to position the mask system.

Another aspect of the invention relates to a mask assembly for use inmedical applications including an upper end and a lower end wherein theupper end is adapted to cover the nose and the lower end is adapted tocover the mouth of a patient. The mask assembly includes no foreheadsupport and includes two stiffened members attached to the upper end onopposed sides of the mask assembly, and wherein the stiffened membersinclude a general curved shape and adapted to avoid covering thepatient's field of vision.

Another aspect of the invention relates to a cushion for attaching to amedical mask, wherein the cushion is flexible and includes a membraneattached to the circumference of the cushion adapted to seal against theface of a patient, and at least one undercushion adapted to support themembrane and positioned underneath the membrane to prevent collapse ofthe membrane, in use. The membrane is softer than the undercushion. Theundercushion in the regions of nasal bridge or chin is between 0 mm and30 mm in height as measured between the base and the tip of theundercushion.

Another aspect of the invention relates to a mask assembly for use inmedical applications including an upper end and a lower end wherein theupper end is adapted to cover the nose and the lower end is adapted tocover the mouth of a patient. The mask assembly includes no foreheadsupport and includes two stiffened members attached to the upper end onopposed sides of the mask assembly, and wherein the stiffened membersinclude a general curved shape and adapted to avoid covering thepatient's field of vision.

In an alternative embodiment, the mask system may include a headgearconnector or rigidizer structured to attach to the frame with asnap-fit, mechanical interlock, friction fit, and/or grommet arrangement(e.g., constructed of rubber).

In an alternative embodiment, the mask system may include headgearhaving an arrangement of straps constructed of silicone and/orBreath-O-Prene™ material.

Other aspects, features, and advantages of this invention will becomeapparent from the following detailed description when taken inconjunction with the accompanying drawings, which are a part of thisdisclosure and which illustrate, by way of example, principles of thisinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings facilitate an understanding of the variousembodiments of this invention. In such drawings:

FIG. 1 is a front perspective view of a mask system according to anembodiment of the present invention;

FIG. 1B is a perspective view showing the mask system of FIG. 1 withheadgear positioned on a patient's head;

FIG. 1C is a cross-sectional view through the mask system of FIG. 1;

FIG. 1D is another cross-sectional view through the mask system of FIG.1;

FIG. 1E is a side view of the mask system of FIG. 1;

FIG. 2 is a front perspective view showing the frame and cushion of themask system of FIG. 1;

FIG. 3 is an exploded perspective view of the mask system of FIG. 1showing the frame, cushion, shroud, and elbow;

FIG. 4 is another exploded perspective view of the mask system of FIG. 1showing the frame, cushion, and shroud;

FIG. 5 is an exploded perspective view of the mask system of FIG. 1showing the shroud and assembled frame/cushion;

FIG. 6 is a front perspective view showing the shroud of the mask systemof FIG. 1;

FIG. 7 is a front perspective view showing the cushion of the masksystem of FIG. 1:

FIG. 8 is a cross-sectional view showing a portion of the cushion ofFIG. 7;

FIG. 8B is a cross-sectional view through nasal bridge and chin regionsof the cushion of FIG. 7;

FIG. 9 is a plan view of headgear laid out flat according to anembodiment of the present invention;

FIG. 10 is a front perspective view of a mask system according toanother embodiment of the present invention;

FIG. 11 is a front perspective view showing the frame of the mask systemof FIG. 10:

FIG. 12 is a front view showing the frame of the mask system of FIG. 10;

FIG. 13 is a side view showing the frame of the mask system of FIG. 10;

FIG. 14 is a front perspective view showing the shroud of the masksystem of FIG. 10:

FIG. 15 is a front view showing the shroud of the mask system of FIG.10:

FIG. 16 is a side view showing the shroud of the mask system of FIG. 10:

FIG. 17 is a rear perspective view showing the shroud of the mask systemof FIG. 10:

FIGS. 18-1 to 18-2 are cross-sectional views showing in sequentialrelation attachment of the shroud to the frame of the mask system ofFIG. 10:

FIGS. 19-1 to 19-4 are cross-sectional views showing in sequentialrelation attachment of the shroud to the frame of the mask system ofFIG. 10;

FIG. 20 is a perspective view showing an alternative arrangement forattaching the shroud to the frame;

FIG. 21 is a rear perspective view showing the shroud of the mask systemof FIG. 10:

FIG. 22 is a cross-sectional view showing attachment of the shroud tothe frame of the mask system of FIG. 10;

FIG. 23 is a cross-sectional view showing attachment of the shroud,frame, and elbow of the mask system of FIG. 10;

FIG. 24 is a cross-sectional view showing an alternative arrangement forattaching the shroud to the frame;

FIG. 25 is a front perspective view of a mask system according toanother embodiment of the present invention:

FIG. 26 is a rear perspective view of the mask system of FIG. 25:

FIG. 27 is a front perspective view of a mask system according toanother embodiment of the present invention;

FIG. 28 is an exploded view of the mask system shown in FIG. 27:

FIG. 29 is an enlarged front perspective view of the mask system shownin FIG. 17;

FIG. 30 is a side view of the mask system shown in FIG. 27;

FIGS. 31-1 is a rear view of a cushion according to an embodiment of thepresent invention;

FIG. 31-2 is a front view of the cushion shown in FIG. 31-1 with apartial cut-away;

FIG. 31-3 is a cross-section view through line 31-3-31-3 in FIG. 31-1;

FIG. 31-4 is a cross-section view through line 31-4-31-4 in FIG. 31-1;

FIG. 31-5 is a cross-section view through line 31-5-31-5 in FIG. 31-1;

FIGS. 32-1 to 32-3 illustrate top, front, and side views respectively ofa concertina section according to an embodiment of the presentinvention;

FIG. 33 is a side view of a mask system according to a variation of thepresent invention;

FIG. 34 illustrates a cushion including a concertina section accordingto an embodiment of the present invention;

FIGS. 35-1 to 35-3 are front, side, and rear views of a mask systemaccording to another embodiment of the present invention:

FIG. 36 is a perspective view of a shroud for a mask system according toan embodiment of the present invention:

FIGS. 37-1 to 37-3 are perspective, front, and side views of a masksystem according to another embodiment of the present invention;

FIGS. 38-1 to 38-5 are perspective, front, top, side, and bottom viewsof a shroud of the mask system shown in FIGS. 37-1 to 37-3;

FIGS. 39-1 to 39-6 are perspective, front, side, bottom, and top viewsof a mask system according to another embodiment of the presentinvention;

FIGS. 40-1 and 40-2 are perspective and side views of a mask systemaccording to another embodiment of the present invention;

FIG. 40-3 is a perspective view of the frame of the mask system shown inFIGS. 40-1 and 40-2:

FIGS. 40-4 and 40-5 illustrate a retaining member of the frame shown inFIG. 40-3;

FIGS. 40-6 and 40-7 illustrate a clip-on upper headgear connector of themask system shown in FIGS. 40-1 and 40-2:

FIGS. 41-1 and 41-2 are rear and front perspective views of a masksystem according to another embodiment of the present invention:

FIGS. 41-3 and 41-4 are exploded views of the mask system shown in FIGS.41-1 and 41-2:

FIGS. 41-5 to 41-12 are various views of a clip-on upper headgearconnector of the mask system shown in FIGS. 41-1 and 41-2;

FIG. 42-1 is a rear perspective view of a mask system according toanother embodiment of the present invention;

FIG. 42-2 is an exploded view of the mask system shown in FIG. 42-1;

FIGS. 42-3 to 42-7 are various views of a clip-on upper headgearconnector of the mask system shown in FIG. 42-1;

FIGS. 43-1 to 43-4 are perspective, side, front, and rear views of amask system according to another embodiment of the present invention;

FIG. 44 illustrates a mask system according to another embodiment of thepresent invention; and

FIG. 45 illustrates a mask system according to another embodiment of thepresent invention.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

The following description is provided in relation to several embodimentsor examples which may share common characteristics and features. It isto be understood that one or more features of any one embodiment orexample may be combinable with one or more features of the otherembodiments or examples. In addition, any single feature or combinationof features in any of the embodiments or examples may constituteadditional embodiments or examples.

In this specification, the word “comprising” is to be understood in its“open” sense, that is, in the sense of “including”, and thus not limitedto its “closed” sense, that is the sense of “consisting only of”. Acorresponding meaning is to be attributed to the corresponding words“comprise”, “comprised” and “comprises” where they appear.

The term “air” will be taken to include breathable gases, for exampleair with supplemental oxygen.

The term “shroud” will be taken to include components that partially orfully cover a second component within the illustrated embodiments. In anembodiment, the shroud may include the component that partially coversor is mounted on the frame components of the illustrated embodiments.

The term “positive connection” will be taken to include connectionsbetween components of the illustrated embodiments wherein connectorsmounted on respective components are adapted to engage each otherrespectively.

1. Mask System

Embodiments of the invention are directed towards a mask system providedwithout a forehead support adapted to engage the patient's forehead.Such arrangement provides the mask system with a less obtrusivearrangement which does not significantly affect the patient's field ofview. Although the system is designed such that a forehead support isnot required, such a forehead support can be added if desired.

As described in greater detail below, the mask system includes a frame,a cushion provided to the frame and adapted to form a seal with thepatient's face, a shroud provided to the frame and adapted to attachheadgear, and an elbow provided to the frame and adapted to be connectedto an air delivery tube that delivers breathable gas to the patient.Headgear may be removably attached to the shroud to maintain the masksystem in a desired adjusted position on the patient's face. The masksystem is intended for use in positive pressure therapy for users withObstructive Sleep Apnea (OSA) or another respiratory disorder.

While each embodiment below is described as including a full-face ororo-nasal interface type, each embodiment may be adapted for use withother suitable interface types. That is, the interface type is merelyexemplary, and each embodiment may be adapted to include other interfacetypes, e.g., nasal interface, nasal mask, nasal prongs, etc.

2. Stabilizing Mechanisms

The stabilizing mechanisms (e.g., frame, shroud, headgear withassociated headgear vectors) of a mask system according to embodimentsof the invention are structured to accommodate the elimination of aforehead support from a full-face type interface. For example, aforehead support typically eliminates rotation of the mask system in thesagittal and coronal planes, so the mask system and headgear accordingto embodiments of the invention are structured to take on thesefunctions since there is no forehead support.

The headgear is connected to the top and bottom of the frame eitherdirectly or via the shroud, which shroud provides headgear connectionpoints for headgear positioned and arranged to stably maintain the masksystem in position on the patient's face.

2.1 Frame

As shown in FIGS. 1, 1B-1E, and 2-5, the frame 1040 of the mask system1010 is structured to maintain the cushion 1060, shroud 1020, and elbow1070 in an operative position with respect to the patient's face. Theframe 1040 is constructed (e.g., injection molded) from a more rigidmaterial (e.g., polyurethane) than the cushion 1060 (made of, e.g.,silicone), however other materials may function likely as well (e.g.,polycarbonate). In an embodiment, the frame has a general wall thicknessof about 1-2 mm, e.g., 1.5 mm.

The frame 1040 defines a breathing chamber or cavity adapted to receivethe patient's nose and mouth and provide air communication to thepatient. One or the lower portion of the frame 1040 includes an opening1046 adapted to receive or otherwise communicate with the elbow 1070(e.g., swivel elbow) and another or upper portion of the frame 1040includes a vent arrangement 1076 for gas washout. In addition, the upperportion of the frame 1040 includes an interfacing structure 1048 adaptedto interface or otherwise removably connect to the shroud 1020.

FIGS. 27-30 shows a mask system 10 including a frame 40 with a cushion44 that provides a sealing portion or sealing ring adapted to form aseal with the patient's nose and/or mouth. Also, the frame 40 includesan opening 46 that is adapted to communicate with the elbow 70.

2.2 Shroud

As shown in FIGS. 1 and 3-6, the shroud 1020 is connected to the frame1040 and is structured to attach headgear to the mask system. In anembodiment, the shroud 1020 is constructed (e.g., injection molded) of aresilient material including but not limited to plastic or nylon (e.g.,Nylon 12). However, the shroud may be constructed of other suitablematerials, e.g., polycarbonate, polypropylene, thermoplastic elastomer(TPE), Pocan®, etc. In an embodiment, the shroud has a general wallthickness of about 1-2 mm, e.g., 1.3 mm.

The top end of the shroud 1020 is adapted to be positioned proximal tothe nasal bridge region or nose of the patient and the bottom end isadapted to be positioned proximal to the mouth or chin of the patient.The top end includes an opening or vent receiving hole 1021 toaccommodate the vent arrangement 1076 that protrudes from the frame1040, and the bottom end includes an opening or elbow hole 1032 toaccommodate the elbow 1070 and elbow opening into the frame 1040 (e.g.,shroud provides no contact with elbow when assembled).

Upper headgear connectors 1024 extend from each side of the top end, andlower headgear connectors 1025 extend from each side of the lower end.The headgear connectors 1024, 1025 may be integrally molded or otherwiseattached to the shroud.

2.2.1 Upper Headgear Connectors

Each upper headgear connector 1024 includes an elongated arm 1026 and aslot or receiving hole 1027 at the free end of the arm 1026 adapted toreceive a respective headgear strap. In use, the arms 1026 extend aroundthe face of the patient in a generally concave angle below the eyes ofthe patient so as to avoid the patient's field of view, i.e., directheadgear away from the patient's eyes. For example, as shown in FIG. 1E,each arm 1026 may extend at an angle α between about 10-25° (e.g., 170)with respect to horizontal. That is, each arm 1026 is suitably formed,shaped, or contoured to follow the contours of the patient's face andavoid line of sight in use. In an embodiment, the shape of the arms maybe generally arcuate and adapted to extend in a direction across thecheek of the patient, while avoiding the eyes or limiting the field ofvision. In an embodiment, the arms may be integrally molded to theshroud of the mask system. One possible advantage of molding the armsonto the shroud is that it greatly increases manufacturability and alsothe shroud may be easily replaced in the case of accidental breakage ofthe arms rather than replacing the complete mask system. Additionally,molding of the arms onto the shroud may greatly increase the strength ofthe connection and reduce or limit the actual likelihood of breakage ofthe arms.

In an embodiment, the arms 1026 are at least semi-rigid (e.g.,relatively rigid) so as to prevent up and down movement or bending ofthe arms relative to the face of the patient. Thus, the arms 1026 mayact as rigidizers to effectively act as a level arrangement and generatea mechanical advantage wherein the pressure or force applied to top endof the mask system is readjusted to a fulcrum point being about thecenter of balance between the top and bottom ends of the mask system. Inan embodiment, the arms are attached to the highest possible pointrelative to the mask system to additionally stabilize the configuration.In an embodiment, the fulcrum point or moment of pivoting is positionedbetween the upper and lower connection points of the straps, and whereinthe design, angle, length and/or configuration of the arms 1026 mayeffectively adjust the fulcrum point. In the illustrated embodiment, thefulcrum point is shown to be between the vent arrangement and elbow ofthe mask system. Additionally, when positioned on the face, the masksystem may have a fulcrum point around or about the region between thebottom of the patient's nose and lip area. This feature effectivelystabilizes the mask system on the patient's face without the traditionalneed for a forehead support.

The net result of the arms 1026 mounted in a position extending from thetop end of the mask system around the face of the patient is that themask system is more stable and reduces the net torsional forcesexperiences about the x-axis 1001 (see FIG. 1) for the mask system inuse. Please note that the arms 1026 may be rigidly connected to the masksystem in other suitable positions to generate a similar result.

In an embodiment, the arms 1026 may be used to stabilize the mask systemby contacting the patient's face at the cheeks. A cheek pad may beprovided to the inner surface of the arm to support the arm on thepatient's cheek in use. Also, the arms 1026 may be enveloped in a softfabric sleeve to act as additional padding against the cheeks of thepatient. The soft fabric sleeve may be in the configuration of anelastic tube covering a portion of the arms 1026.

2.2.2 Lower Headgear Connectors

Each lower headgear connector 1025 includes an abbreviated arm and aclip receptacle 1031 at the free end of the arm adapted to be removablyinterlocked with a headgear clip associated with a respective headgearstrap. The clips allow for easier positioning or donning/removal of themask system. In an embodiment, the abbreviated arms and clips are alsorelatively rigid so as to prevent lateral movement of the arms along they-axis 1002, relative to the mask system in use.

FIGS. 27-30 illustrate an exemplary headgear clip 33 adapted to beremovably interlocked with a clip receptacle 31. As best shown in FIG.28, each clip 33 includes two spring arms 35 adapted to interlock withthe respective clip receptacle 31 with a snap-fit and a slot 37 adaptedto receive a respective headgear strap in use.

2.2.3 Alternative Headgear Connectors

As shown in FIGS. 27-30, the arm 26 may be removably coupled to theshroud, e.g., arm 26 includes clip structure adapted to removablyinterlock with a clip receptacle provided to the shroud. Thisarrangement allows different styles of upper and lower headgearconnectors to be used with the shroud, e.g., arms for both upper andlower headgear connectors, clips for both upper and lower headgearconnectors, different length arms for upper and lower headgearconnectors, etc.

However, the shroud may provide other suitable arrangements forattaching headgear straps of headgear. Also, the shroud may include oneor more additional components, e.g., forehead support.

2.2.4 Headgear Connector Positioning

In the embodiment of FIGS. 1-6, the upper and lower headgear connectors1024, 1025 provide headgear connection points that are as far from eachother as possible (i.e., top and bottom of frame) to allow for greateradjustability (e.g., allows adjustment at the top and bottom of the masksystem) and stability (e.g., anchor points spread out around the masksystem so more secure on the patient's face). Also, the upper headgearconnectors are positioned as close to the top of the mask system aspossible without obstructing the patient's eyes in use.

2.2.5 Separate Shroud

In the embodiment of FIGS. 1-6, the shroud 1020 is formed separately(e.g., molded) and attached to the frame 1040. Such arrangementfacilitates molding of the shroud, allows different materials to be usedfor the frame and shroud (e.g., frame can be semi-rigid or rigid forstability and shroud with headgear rigidizers can be flexible foradjustment, allows the shroud to hide elbow retention features aroundelbow/frame opening for retaining elbow to frame (e.g., provides visualshroud for aesthetics), allows frame to be free of lower clipreceptacles, allows shroud to be used with different size frames, andallows the shroud to be designed or stylized to minimize obtrusivenessof the mask system. The separate shroud may also allow the headgear,frame, cushion, and/or elbow to be replaced or washed independently.

2.2.6 Sleeves

In an embodiment, soft fabric sleeves may be mounted on the upper and/orlower headgear connectors. For example, the sleeves may be elastic andadapted to slide over the arms of the headgear connectors to form atight fit. In an embodiment, the sleeves form elastic tubes. The sleevesmay be padded to increase the comfort of the mask system in use. Thesleeves may be particularly useful where the arms of the headgearconnectors contact the patient's skin, e.g., to protect the patient'sskin from irritation.

2.2.7 Arm Extends Over the Patient's Ear

FIGS. 35-1 to 35-3 and 36 illustrate a shroud 220 for mask system 210according to another embodiment of the present invention. The shroud 220includes an annular retaining portion 222 structured to retain the frame240 and upper and lower headgear connectors 224, 225 on each side of theretaining portion 222. In the illustrated embodiment, the shroud 220 isintegrally formed in one piece (e.g., see FIG. 36).

In the illustrated embodiment, each upper headgear connector 224includes an elongated arm 226 and a slot 227 at the free end of the arm226 adapted to receive a respective rear strap 298 in use. Asillustrated, the arm 226 is suitably contoured to extend along thecheeks and over the patient's ear just anterior of the patient's templeand retain the respective rear strap 298 in spaced relation over thepatient's ear, e.g., to avoid the strap rubbing or irritating thepatient's ear in use.

Also, each arm 226 is structured to extend along and engage an upperstrap 292 of the headgear in use. As illustrated, each arm 226 issecured to the upper strap 292 to add rigidity to the strap andstabilize the mask system on the patient's face in use. In addition, thestrap 292 provides padding to the arm 226 on the patient's face in use.In an embodiment, the upper strap 292 may be fixed to the arm 226 bygluing or stitching for example. Alternatively, the arms 226 may beencapsulated by or inserted into respective straps 292 so that the arms226 are substantially not visible.

Each lower headgear connector 225 includes an abbreviated arm 228 with aslot 229 at the free end of the arm 229 adapted to receive a respectivelower strap 294 in use. As illustrated, the arm 228 is suitably orientedto retain the respective lower strap 294 in spaced relation under thepatient's ear, e.g., to avoid the strap rubbing or irritating thepatient's ear in use.

In an embodiment, each arm may be attached to the upper end of the masksystem and curves below the patient's field of vision or eyes and curvesupwards at an angle between about 10 to 20 degrees away from thehorizontal axis.

In an alternative embodiment, as shown in FIG. 36, each lower headgearconnector 225 may include a clip receptacle 231 adapted to be removablyinterlocked with a headgear clip (not shown) associated with arespective lower strap 294. In an embodiment, the headgear clipreceptacle and clip may be similar to that on ResMed's Mirage Liberty™mask. Exemplary clip arrangements are disclosed in U.S. PatentPublication Nos. 2007/0144525 and 2006/0283461, each of which isincorporated herein by reference in its entirety.

2.2.8 Shroud without Upper Headgear Connector

FIGS. 37-1 to 37-3 illustrate a mask system 310 according to anotherembodiment of the present invention. As illustrated, the mask system 310includes a shroud 320, a frame 340, a cushion 344, and an elbow 370.

As best shown in FIGS. 38-1 to 38-5, the shroud 320 includes an opening322 structured to receive the elbow 370 and a headgear connector 325 oneach side thereof. In the illustrated embodiment, each headgearconnector 325 includes a clip receptacle 331 adapted to be removablyinterlocked with a headgear clip (not shown) associated with arespective lower headgear strap.

The frame 340 is removably attached to the shroud 320, e.g., fingers andtabs 345 extending from opening 322 adapted to engage collar of frame340.

The frame 340 includes an upper headgear connector 324 on each upperside thereof. Each headgear connector 324 includes a clip retainer 333adapted to be removably interlocked with a headgear clip (not shown)associated with a respective upper headgear strap.

FIGS. 39-1 to 39-6 illustrate an alternative version of the mask system310, which is indicated with similar reference numerals. As illustrated,the frame 340 is provided without upper headgear connectors, and theeach clip receptacle 331 includes an alternative configuration (e.g.,holes for snap-fit tabs on the clip). Also, the shroud 320 in FIGS. 39-1to 39-6 includes support bars 329 structured to wrap around respectiveauxiliary ports 343, while the shroud 320 in FIGS. 37-1 to 38-5 includessupport bars 329 that extend in front of respective auxiliary ports 343.

2.3 Headgear

Headgear may be removably attached to the headgear connectors 1024, 1025of the shroud 1020 to maintain the mask system 1010 in a desiredposition on the patient's face, e.g., see FIG. 1B.

As shown in FIG. 9, the headgear 1090 includes a pair of upper and lowerstraps 1092, 1094 with the upper straps 1092 removably attached torespective upper headgear connectors 1024 and the lower straps 1094removably attached to respective lower headgear connectors 1025. Thefree end of each strap may include a Velcro® tab structured to engagethe remainder of the strap to secure the strap in place. Such Velcro®attachment also allows adjustment of the length of the straps. However,the upper and lower headgear straps may be secured to the shroud in anyother suitable manners, e.g., adjustable ladder-lock arrangement, etc.

The upper straps 1092 split at the crown of the patient's head to topstraps 1096 (e.g., connected to one another by a buckle) adapted to passover the top of the patient's head in use and rear straps 1098 adaptedto pass behind the patient's head in use. In an embodiment, the headgear1090 is structured to be self-supporting.

In FIG. 9, the top straps 1096 are adapted to be connected to oneanother by a buckle. In an alternative embodiment, as shown in FIG.27-30, headgear 90 may include upper and lower straps 92, 94, top strap96, and rear strap 98, with the top straps 96 integral with one another.

The upper straps 1092 are designed to adjust the position of the mask ina similar way that an adjustable forehead support would alter theposition of the mask system, i.e., move the top of the mask systemcloser or further away from the patient's nasal bridge.

Without the forehead support, the headgear is connected at the top andbottom of the mask frame 1040 via the shroud 1020, and in order to avoidthe eyes and ears, the arm 1026 of the upper headgear connector extendsat an angle. In doing so, the headgear vectors V1 and V2 (see FIGS. 1and 1B) are aligned such that the mask system may have a tendency toride up the patient's face (i.e., upper headgear connectors positionupper headgear vectors upwardly from horizontal and lower headgearconnectors position lower headgear vectors generally horizontal). Bysplitting the upper headgear strap 1092 at the crown of the patient'shead (i.e., top and rear straps 1096, 1098), the upper headgear vectorsare realigned to prevent the mask system from sliding up the patient'sface.

2.3.1 Headgear Adjustment

FIGS. 35-1 to 35-3 illustrate headgear 290 attached to the headgearconnectors 224, 225 of the shroud 220 to maintain the mask system in adesired position on the patient's face.

In the illustrated embodiment, the headgear 290 includes a pair of upperor top straps 292, a pair of lower or bottom straps 294, and a pair ofrear straps 298. In use, the upper straps 292 are secured to respectiveupper connectors or arms 226, the lower straps 294 are removablyattached to respective lower connectors via slots 229/clip arrangement231, and the rear straps 298 are removably attached to respective upperconnectors via slots 227. The upper straps 292 may include upper strapportions adapted to pass over the top of the patient's head and coupleto one another, e.g., via a headgear buckle or adjustable ladder-lockarrangement 299. In the illustrated embodiment, the lower straps 294 andrear straps 298 are formed in one piece.

This headgear arrangement allows adjustment to occur at three positions,i.e., upper straps 292 at the headgear buckle 299, lower straps 294 atthe slot 229/clip 231 connection, and rear straps 298 at the slot 227connection.

As illustrated, the free end of each strap may include a hook and looptab 295 (e.g., Velcro®) structured to engage the remainder of the strapto removably secure the strap in place. Such hook and loop attachmentalso facilitates adjustment of the length of the straps.

In the illustrated embodiment, the lower straps 294 and rear straps 298are adapted to join and pass behind the patient's head in use (e.g., seeFIG. 35-3). As illustrated, the lower straps 294 join at an angle α(e.g., similar to the bottom strap in ResMed's Mirage Liberty mask) toprevent the strap from irritating the patient's neck and/or preventmovement of the strap due to movement of the patient's neck in use.

In an embodiment, the headgear may be similar to that for ResMed'sMirage Liberty mask, however the top straps have been modified and thereis an added rigidizer system. The top straps may be similar to ResMed'sSwift style headgear, with the rigidizers extending along the sides.

2.3.2 Alternative Headgear Material

FIGS. 43-1 to 43-4 illustrate a mask system 610 including a mask 615 andheadgear 690 according to another embodiment of the present invention.In the illustrated embodiment, the headgear 690 includes an arrangementof straps wherein some of the straps are constructed of silicone andsome of the straps are constructed of Breath-O-Prene™ material. However,the headgear may be constructed such that the straps are completelyconstructed of silicone or completely constructed of Breath-O-Prene™.

As illustrated, the lower strap portion 692 of the headgear isconstructed of Breath-O-Prene™ and extends along the cheeks and aroundthe back of the patient's head. The upper strap portion 694 of theheadgear is constructed of silicone and includes side straps 694(1) thatextend along the upper cheek and over the patient's ear, a top strap694(2) that extends over the top of the patient's head, rear straps694(3) that extend behind the patient's head and connects to the lowerstrap portion 692 (see FIG. 43-4), and connecting portions 694(4) thatextend from respective side straps 694(1) in front of the patient's earand connect to the lower strap portion 692.

The headgear straps may be connected to the mask in any suitable manner.For example, in the illustrated embodiment, the lower strap portion 692is connected to the mask by a headgear clip arrangement and the upperstrap portion 694 is connected to the mask using an elongated buckle 695with buckle portions on each end thereof

In an embodiment, the headgear straps are arranged such that the forcevectors applied by the headgear to the mask are substantiallyperpendicular to the mask and substantially parallel to one another(e.g., as shown by the arrows in FIG. 43-2). This arrangement enhancesthe mask seal as the headgear forces the mask directly into thepatient's face.

3. Seal

The seal (i.e., cushion) of the mask system is structured to accommodatethe elimination of a forehead support from a full-face type interface.

3.1 Cushion

As shown in FIGS. 1-5 and 7-8, the cushion 1060 is structured tointerface with the frame 1040 and form a seal with the patient's noseand mouth in use. In the illustrated embodiment, the cushion is afull-face cushion adapted to engage the patient's face generally alongnasal bridge, cheek, and lower lip/chin regions of the patient's face.However, other cushion interfaces are possible, e.g., nasal.

The cushion 1060 is structured be more compliant or flexible (e.g.,particularly in the nasal bridge region) to accommodate more movementdue to loss of some stability without a forehead support.

The cushion 1060 is constructed of a soft and flexible biocompatiblematerial, e.g., such as silicone. In the illustrated embodiment, thecushion 1060 includes a dual wall configuration wherein the cushioncomprises an undercushion or support wall 1062 underneath a membrane1064 as shown in FIG. 8.

The membrane 1064 is generally softer and less stiff than theundercushion 1062 and provides a seal against the patient's face in use.The membrane may be relatively thin to allow for wider fit range andbetter conformance to the patient's face in view of less mask stabilitywith a forehead support. The undercushion is structured to generallysupport the membrane and prevents collapse of the membrane when the masksystem is attached and tightened using the headgear.

The membrane 1064 is generally concave and curves inwards towards thebreathing chamber. The undercushion 1062 may also curve inwardly but isgenerally shorter, thicker, and more rigid than the membrane.

In an embodiment, the undercushion 1062 at the regions of the nasalbridge and/or chin of the patient is shorter in height or completelyabsent and the height from the tip to base of the undercushion 1062 maybe between about 0 mm and 30 mm. The membrane is generally longer thanthe undercushion 1062 at any given cross-section and may be betweenabout 1 mm and 40 mm. For example, FIG. 8B illustrates a cross-sectionthrough nasal bridge and chin regions of the cushion to illustrate themembrane 1064 without an undercushion in these regions.

In an embodiment, the undercushion 1062 may only be provided in selectedregions of the mask system, e.g., where the mask system is to be pushedaway from the patient's face. Certain pre-determined regions of thepatient's face may be preferably avoided for applying pressure by thetightening of the headgear. In the illustrated embodiment, the nasalbridge and chin regions of the patient do not include an undercushion1062. In these regions, the undercushion is only provided along lateralsides of the cushion (e.g., see FIG. 7) which press against the cheeksof a patient so as to more evenly distribute the force vectors appliedby the mask system in use. In an embodiment, the undercushion may berelatively stiff along the cheek regions because these points of contactare acting as anchor points, i.e., holds mask system in position toprovide effective seal.

This configuration of avoiding the nasal bridge and chin of the patientmay increase the comfort of the mask system for patients by reducing thepressure or force applied to sensitive areas or to protruding regions ofthe patient's face that experience relatively higher contact pressures.Additionally, this arrangement avoids the cushion pinching the nasalbridge of the patient when the mask system is adjusted. Additionally,the cushion of this embodiment may be noticeably softer in the regionsof the nasal bridge and chin because of the absence of the undercushion.

In an embodiment, the undercushion may include a variable height,stiffness, and/or thickness to generate a variable softness in theaforementioned predetermined regions of the face that require lightersupport.

In the illustrated embodiment, the cushion may be structured to seallower down on the patient's nasal bridge and the eye sockets so that thecushion is less obtrusive.

In an embodiment, the cushion may be generally frosted except at patientcontacting surfaces where it is polished. In an embodiment, the frostingof the cushion may reduce restriction between the face and membraneand/or the membrane and undercushion. The frosting allows the surface ofthe membrane and undercushion to slide against each other's respectivesurface without the same restriction of unfrosted silicone. This featuremay also prevent or limit sticking of the membrane to the undercushioncomponents and also may generally improve the overall comfort andsealing properties of the cushion. Additionally, the frosting of thecushion may be easier to manufacture and may lead to a reduction ofcosts of manufacturing. The cushion may be constructed of frostedsilicone or other suitable materials.

3.2 Cushion Lower on Nasal Bridge

FIGS. 31-1 to 31-5 illustrate various views of a cushion 44 (e.g.,constructed of silicone) according to an embodiment of the presentinvention. As illustrated, the cushion 44 includes a base wall 44(1)provided to the frame, an undercushion layer (UCL) 44(2) extending awayfrom the base wall 44(1), and a membrane 44(3) provided to substantiallycover the UCL 44(2) and provide a sealing structure. In the illustratedembodiment, the cushion 44 is structured to sit lower on the nasalbridge to reduce mask obtrusiveness and improve “line of sight” in use.

Also, as best shown in FIGS. 31-3 and 31-5, the UCL 44(2) design in thenasal bridge region is structured to provide improved stability acrossthe nasal bridge in use. As shown in FIGS. 31-1 and 31-3, the UCL is notprovided in the lower lip/chin region. However, other arrangements ofthe UCL are possible, e.g., UCL around entire perimeter.

In an embodiment of the cushion shown in FIGS. 31-1 to 31-5, D1 may beabout 15-20 mm, e.g., 18.2 mm. D2 may be about 53-59 mm, e.g., 55.8 mm,D3 may be about 88-93 mm, e.g., 90 mm, D4 may be about 78-83 mm, e.g.,81.1, D5 may be about 58-63 mm, e.g., 60 mm, D6 may be about 95-100 mm,e.g., 98.1 mm, D7 may be about 57-62 mm, e.g., 59.7 mm, D8 may be about77-82 mm, e.g., 79 mm, D9 may be about 88-93 mm, e.g., 90.7 mm, D10 maybe about 30-35 mm, e.g., 33.1 mm, D11 may be about 14-19 mm. e.g., 16.4mm, D12 may be about 8-13 mm, e.g., 9.6 mm. D13 may be about 0.3-0.5 mm,e.g., 0.35 mm, D14 may be about 0.4-0.6 mm, e.g., 0.5 mm, and D15 may beabout 0.3-0.5 mm, e.g., 0.4 mm. Although specific dimensions and rangesare indicated, it is to be understood that these dimensions and rangesare merely exemplary and other dimensions and ranges are possibledepending on application. For example, the exemplary dimensions may varyby 10-20% or more or less depending on application.

3.3 Cushion Higher on Nasal Bridge

FIGS. 35-1 and 35-2 illustrate a full-face cushion 244 adapted to engagethe patient's face generally along nasal bridge, cheek, and lowerlip/chin regions of the patient's face. In this embodiment, the cushion244 is structured such that it is positioned higher on the bridge of thenose for sealing and comfort (e.g., with respect to the cushion 44described above). The cushion 244 may also be better foranthropometrics, i.e., the cushion will fit more people.

In an embodiment, the cushion 244 may include a concertina section asdescribed below (e.g., in the nasal bridge region) to enhance theflexibility of the cushion in use.

3.4 Concertina Section

As best shown in FIGS. 30 and 33, a concertina section 50 may beprovided in a nasal bridge region of the cushion and/or frame. Asillustrated, the concertina section 50 includes a bellows structure withone or more folds 52 that provide a higher degree of flexibility orincreased movement. That is, the concertina section 50 provides a higherlevel of adaptability or flexibility to the nasal bridge region of thecushion/frame which is a more sensitive region of the patient's face inuse. Moreover, the concertina section 50 provides increased movementwithout compromising seal.

FIGS. 32-1 to 32-3 illustrate various views of a concertina section 50(isolated from the remainder of the cushion/frame) with one or morefolds 52 according to an embodiment of the present invention. As bestshown in FIG. 32-3, the folds may have different lengths, depths, and/orcontours with respect to one another to optimize the concertina effect,e.g., provide sufficient degree of movement without compromising seal.For example, as shown in FIG. 32-3, each fold 52 includes a first sidewall 52(1) and a second side wall 52(2) that interconnects adjacent sidewalls 52(1).

In the illustrated embodiment, the first side walls 52(1) and/or thesecond side walls 52(2) may become progressively longer away from thepatient's face. For example, the first side wall 52(1) and/or the secondside wall 52(2) adjacent patient's face, or the combination of sidewalls 52(1) and 52(2), may have a length that is longer than and in somecases significantly longer than the adjacent side wall 52(1) and/or52(2) (e.g., one side wall at least 25% greater than and up to 5× aslong as the other side wall, e.g., 1×, 2×, 3×, or 4×).

The folds may be constructed and arranged to provide a predeterminedorder of movement or folding, e.g., folds structured to fold in asequential or progressive manner wherein one fold collapses before anadjacent fold collapses. For example, upon application of force, thefolds closest to the patient's face may fold or collapse before thefolds furthest from the patient's face. Also, the folds may beconstructed and arranged to provide various degrees of fold or collapse,e.g., folds may fold or collapse more than others.

In an embodiment of the concertina section shown in FIGS. 32-1 to 32-3,D1 may be about 50-60 mm, e.g., 55.7 mm, D2 may be about 5-15 mm, e.g.,9.7 mm, and D3 may be about 0.3-0.5 mm, e.g., 0.4 mm. Although specificdimensions and ranges are indicated, it is to be understood that thesedimensions and ranges are merely exemplary and other dimensions andranges are possible depending on application. For example, the exemplarydimensions may vary by 10-20% or more or less depending on application.

It should be appreciated that a concertina section 50 may be provided inother regions of the cushion and/or frame, e.g., depending on patientcomfort. For example, the concertina section 50 may be provided aroundthe entire perimeter of the cushion and/or frame or may be provided inselected regions of the cushion and/or frame.

Also, the flexibility of the concertina section 50 may be varied and maybe varied in different regions of the cushion and/or frame, e.g.,depending on patient comfort. For example, the cushion and/or frame mayinclude a concertina section in the nasal bridge region with arelatively high degree of flexibility and a concertina section in thelower lip/chin region with a relatively low degree of flexibility. Theflexibility of the concertina section 50 may be varied by varying thenumber of folds 52 (e.g., 1-5 folds), the wall lengths, the wallthickness of the folds 52, the depth of the folds 52, etc.

As noted above, the cushion and frame may be co-molded of two parts withdifferent materials/rigidities or may be integrally formed of the samematerial. In both embodiments, the concertina section may be provided inthe frame and/or the cushion.

In FIGS. 27-30, the cushion 44 and frame 40 are co-molded of two partswith the concertina section 50 provided in the frame 40. The frame 40and cushion 44 include different rigidities in order to optimize thefunction of each part. For example, one part (i.e., cushion 44) may beconstructed of a relatively soft, supple material to optimize thesealing effect and the other part (i.e., frame 40) may be constructed ofa more rigid material to provide adequate support for the cushion whileat the same time allowing a sufficient degree of movement to optimizethe concertina effect. While the frame is more rigid than the cushion,the frame may be constructed of a flexible material to allow theconcertina effect.

In FIG. 33, the frame 40 and cushion 44 are integrally formed in onepiece with the concertina section 50 provided in the frame 40. Thematerial properties and/or dimensions may be selectively modified tooptimize sealing and concertina effects.

For both embodiments of FIGS. 27-30 and 33, it should be appreciatedthat the concertina section may be alternatively provided in the cushion44 or in both the frame 40 and cushion 44. For example, FIG. 34illustrates a concertina section 50 integrally formed with the cushion44 in the nasal bridge region.

4. Elbow

As shown in FIG. 3, the elbow 1070 (e.g., constructed of a relativelyhard material such as polycarbonate or polypropylene) includes a firstend portion 1074(1) and a second end portion 1074(2). The first endportion 1074(1) provides an interfacing structure structured tointerface or otherwise attach to the frame 1040. The second end portion1074(2) is adapted to be connected to an air delivery tube.

4.1 Elbow Connection to Frame

The frame 1040 is structured to maintain the elbow 1070 in an operativeposition with respect to the patient's face. That is, the frame acts asa carrier and bearing surface for the elbow. The frame and elbow mayconnect with a friction fit, snap-fit, mechanical interlock, or othersuitable attachment mechanism. However, other suitable arrangements forattaching the elbow to the frame are possible.

In the illustrated embodiment, the elbow 1070 includes a series of tangs1075 adapted to releasably engage within the opening 1032 of the frame1040, e.g., with a snap-fit. The tangs 1075 hold the elbow in place(e.g., preferably a relatively airtight connection) and permit rotationor swiveling of the elbow with respect to the frame.

That is, the elbow is rotatably attached to the frame so that the elbowmay be rotated relative to the frame in use, e.g., 360° rotation. Thisarrangement allows the elbow to assume different orientations in use,e.g., depending on patient preference. For example, the elbow may assumea first orientation so that the elbow extends generally downwardly fromthe mask to direct the air delivery tube under the patient's head inuse. Alternatively, the elbow may be rotated and assume a secondorientation so that the elbow extends upwardly from the mask to directthe air delivery tube over the patient's head in use. In an embodiment,the frame and elbow may be constructed of dissimilar materials toprevent or at least reduce squeak between the components in use.

The second end portion of the elbow may be provided to a swivel jointadapted to be connected to the air delivery tube. For example, FIGS.27-30 illustrate a swivel joint 80 provided to the second end portion74(2) of elbow 70. In the illustrated embodiment, the swivel joint 80 isprovided to a short tube 82 (e.g., extendable and retractable tube) thatinterconnects the elbow with the air delivery tube. In an embodiment,the swivel joint 80 may be integrally formed in one piece with the shorttube 82.

4.2 AAV

The elbow 1070 includes a slot 1081 to receive an anti-asphyxia valve(AAV), a port 1079 that is selectively closed by a flap portion of theAAV (depending on the presence of pressurized gas), and structure forattaching the AAV, e.g., with a snap-fit.

FIGS. 27-30 illustrate an exemplary AAV 85 including a flap portion 86to selectively close port 79 in elbow 70. In this embodiment, a clipportion 88 is provided to the flap portion 86 for attaching the AAV 85to the elbow 70. In the illustrated embodiment, the flap portion 86 andthe clip portion 88 are co-molded with one another to form a one-piece,integrated component. However, the flap portion 86 and clip portion 88may be secured to one another in other suitable manners, e.g.,mechanical interlock.

In an embodiment, the flap portion 86 may be constructed of a relativelysoft elastomeric material (e.g., silicone) and the clip portion 88 maybe constructed of a more rigid material (e.g., rigid plastic) forinterfacing with the elbow 70.

The clip portion 88 of the AAV 85 includes structure for removablyinterlocking with the elbow 70, e.g., with a snap-fit. For example, theclip portion 88 may include tabs structured to interlock with respectiverecesses/protrusions provided to the elbow.

FIGS. 35-1 and 35-2 illustrate an elbow 270 including a port 279 that isselectively closed by a flap portion 286 of the AAV 285 (depending onthe presence of pressurized gas). Also, FIGS. 37-1 to 37-3 illustrateelbow 370 including a port 379 and a slot 381 to retain the AAV.

Alternative embodiments of the AAV are disclosed in PCT Application No.PCT/AU2006/000031, which is incorporated herein by reference in itsentirety.

4.3 Large Diameter End Portion

As shown in FIGS. 27-30, the first end portion 74(1) of the elbow 70 mayprovide a relatively large diameter which allows the potential forcleaner/smoother lines thereby contributing to the overall maskaesthetic and reduced obtrusiveness. In addition, the relatively largediameter elbow offers the potential for the patient's nose to protrudeinto the elbow cavity thereby permitting the mask to be brought closerto the patient's face (i.e., reduced obtrusiveness), less moment sincecenter of gravity of mask is closer to the patient's face, and/orimproved line of sight.

5. Modular Design

The mask system provides a modular design that allows different stylesand/or sizes of the frame (also referred to as a frame module), shroud(also referred to as a shroud module), cushion (also referred to as acushion module), and/or elbow (also referred to as an elbow module) tobe interchanged or mixed and matched with one another to provide a morecustomized mask system for the patient. In addition, such design allowsselected modules to be easily replaced, e.g., treatment requirementschange, worn out or damaged, etc.

In an embodiment, the mask system may be provided with a number ofdifferent cushions, e.g., each having cushions of different stylesand/or sizes (e.g., depending on patient preference and/or fit). Forexample, the non-face contacting side of each cushion may include acommon or universal configuration for interfacing with the frame, andthe face-contacting side of the cushion may include different stylesand/or sizes. This provides a modular arrangement that allows the frameto be selectively (e.g., and removably) coupled to one of multiplecushion. For example, the different cushions may include different sizecushions (e.g., small, medium, and large) and may include a differentcushion structures.

In an embodiment, the mask system may be provided with differentshrouds, e.g., each shroud having a different style and/or size (e.g.,shroud with different arrangement/style of headgear connectors, shroudwith forehead support, different headgear vectors, etc).

In an embodiment, the mask system may be provided with different frames,e.g., each frame having a different style and/or size (e.g., frame withdifferent vent arrangement, small, medium, and large size frame, etc).

In an embodiment, the mask system may be provided with a number ofdifferent elbows, e.g., each having a vent arrangement, AAV (in the caseof an oro-nasal mask), and/or elbow of different styles and/or sizes. Inthe illustrated embodiment of FIGS. 27-30, the vent arrangement 76 andAAV 85 are structured to be removably attachable to the elbow 70. Thisprovides a modular arrangement that allows the elbow to be selectivelyand removably coupled to one of multiple vent arrangements and/or AAVs.This also allows the vent arrangement and AAV to be easily replaced,e.g., if damaged.

5.1 Shroud to Frame Connection

The shroud is mounted on the outer surface of the frame, e.g.,preferably with a tight, conforming fit on the frame.

5.1.1 Upper Retaining Mechanism

In the illustrated embodiment of FIGS. 1-5, the shroud 1020 is connectedto the frame 1040 by an upper retaining mechanism or interfacingstructure 1048 located on the top end of the frame and shroud.

As shown in FIGS. 2 to 5, the upper retaining mechanism 1048 is in theform of two taper locks structured to secure the shroud 1020 on theframe 1040 and prevent unintentional disassembly particularly due toheadgear forces. In this embodiment, opposing sides of the frame includea female slot 1055 adapted to receive a respective tang protrusion(which tapers along its length) on the underside of the shroud 1020. Thetapered protrusion engages within a respective female slot, e.g., with afriction fit.

FIGS. 10 to 19-4 show another embodiment of a mask system 1110 whichmore clearly illustrates an embodiment of the taper lock. FIGS. 10 to 17show various views of the frame 1140, shroud 1120, and elbow 1170 of themask system 1110.

As best shown in FIGS. 11 to 13, opposing sides of the top end of theframe 1140 include a platform 1154 which provides a first female slot1155(1). In addition, the space between the platform 1154 and the outersurface of the frame 1140 defines a second female slot 1155(2). As bestshown in FIG. 17, opposing sides of the top end of the shroud 1120include a tang protrusion 1156 on the underside of the shroud 1120. Thetang protrusion 1156 includes a first tang 1156(1) and a second tang1156(2) that extends generally transverse to the first tang 1156(1). Asshown in FIGS. 18-1 and 18-2, each tang may taper along its length,i.e., thinner towards its free end.

FIGS. 18-1 and 18-2 and 19-1 to 19-4 sequentially illustrate attachmentof the shroud 1120 to the frame 1140. As illustrated, the tangs 1156(1),1156(2) of each tang protrusion 1156 are structured to engage withrespective slots 1155(1). 1155(2), e.g., with a friction fit. As bestshown in FIGS. 19-1 to 19-4, each slot 1155(2) includes lead-ins orguides 1157 that curve along their length (i.e., extend in vertical andhorizontal direction) so as to guide the tang 1156(2) into the slot1155(2) and aid assembly. FIGS. 18-2 and 19-4 show the tangs 1156(1),1156(2) when fully inserted with respective slots 1155(1), 1155(2).

In an alternative embodiment, as shown in FIG. 20, the upper retainingmechanism may include a clip-type arrangement. As illustrated, opposingsides of the top end of the frame 1240 provide a shoulder 1255(1) and atapered protrusion 1255(2). Opposing sides of the top end of the shroud1220 include a first tang 1256(1) and a second tang 1256(2) on theunderside of the shroud 1220. In use, each first tang 1256(1) is engagedwith the respective shoulder 1255(1) and the second tang 1256(2) isengaged or clipped onto the tapered protrusion 1255(2), e.g., with asnap-fit.

5.1.2 Lower Retaining Mechanism

In an embodiment, the shroud may also be connected to the frame by alower retaining mechanism located on the bottom end of the frame andshroud. For example, a retaining mechanism may be provided to theopening of the shroud which is structured to interlock or otherwiseengage with the opening of the frame.

For example, as shown in FIGS. 14, 15, 17, and 21, the opening 1132 ofthe shroud 1120 may include structure adapted to engage the collar 1149surrounding the frame opening 1146 with a snap-fit. As illustrated, theshroud 1120 includes snap fingers 1145(1) (e.g., three snap fingers) andsandwich tabs 1145(2) (e.g., three sandwich tabs) that extend from theopening 1132. The snap fingers and sandwich tabs are alternativelyspaced about the opening.

In use, the snap fingers 1145(1) resiliently deflect (e.g., 0.5 mmdeflection) and engage respective part-annular protrusions 1149(1)provided to the collar 1149 (e.g., see FIGS. 22 and 23) to provide aninitial retention of the shroud 1120 to the frame 1140 (e.g., withallowable stresses), e.g., to facilitate assembly and disassembly. Inaddition, as the snap fingers 1145(1) engage respective protrusions1149(1), the sandwich tabs 1145(2) are received in respective recesses1149(2) provided to the end of the collar 1149 (e.g., see FIGS. 22 and23). When the elbow 1170 is engaged with the frame 1140 (e.g., see FIG.23), an annular protrusion 1171 on the elbow 1170 is positioned on anopposing side of the sandwich tabs 1145(2) so that the sandwich tabs1145(2) are sandwiched between the collar 1149 and the elbow 1170. Thus,the sandwich tabs utilize elbow retention forces to retain the shroud onthe frame during use. The elbow 1170 has a distal shoulder 1173 adaptedto extend under the edge of the frame 1140 to retain the elbow to theframe. The snap fingers 1145(1) allow the shroud to connect to the frameindependent of the elbow.

In an alternative embodiment, as shown in FIG. 24, the shroud's lowersection may be structured to clip to a single point below the collar. Asillustrated, the lower end of the shroud 1320 includes a snap finger1345 that is engaged or clipped onto a protrusion 1349(1) spaced belowthe collar 1349 of the frame 1340, e.g., with a snap-fit. In thisembodiment, the protrusion 1349 extends from the cover enclosingauxiliary ports. This arrangement may facilitate molding of the collaron the frame, e.g., uniform thickness of the collar prevents moldingdistortions. In addition, removal of the protrusions 1149(1)/recesses1449(2) from the collar may reduce the risk of leak.

5.1.3 Finger Grip

In an embodiment, the outer surface of the frame 1040 may include fingergrips or recessed portions 1097, which are positioned to be exposedunder the shroud 1020. The finger grips are adapted to allow the patientan improved ability to grip the frame and/or shroud which isparticularly useful when disengaging the shroud from the frame.

5.1.4 Alternative Interfacing Structure

In an alternative embodiment, as shown in FIG. 27-30, the shroud 20includes an open construction that provides an annular or part annularretaining portion 22 structured to retain the frame 40 and the elbow 70.As illustrated, the annular retaining portion 22 includes an interfacingstructure 23 along an inner edge that is adapted to interface with orotherwise removably connect to an interfacing structure 48 along theouter perimeter of the frame 40 (e.g., see FIG. 28). In the illustratedembodiment, the interfacing structure 23 is in the form of opposedflanges 23(1) that are adapted to interlock with respective lockingstructures 48(1) provided on opposing sides of the frame 40. However,other suitable arrangements for attaching the frame 40 to the shroud 20are possible, e.g., friction fit, snap-fit, mechanical interlock, orother suitable attachment mechanism.

For example, the frame 40 may be coupled to the shroud 20 in a mannerthat allows the frame 40 to be locked in different angular positionswith respect to the shroud 20, e.g., pivotally mounted.

5.1.5 Alternative Upper Headgear Connector

FIGS. 40-1 to 40-7 illustrate a frame and a clip-on upper headgearconnector or rigidizer according to another embodiment of the presentinvention.

The frame 442 includes an opening 449 adapted to engage a frame shroudand/or elbow. Around and under the opening 449 is the u-shaped slot 402for gas washout and auxiliary ports 443 on each side thereof.

In this embodiment, each upper side of the frame 442 includes aretaining member 433 and an upper intermediate portion of the frame 442includes retaining grooves 435, which are structured and arranged toretain an upper headgear connector or rigidizer 424.

As best shown in FIGS. 40-6 and 40-7, the upper headgear connector 424includes a pair of elongated arms or rigidizers 426 coupled by a pair ofwire members 428. Each rigidizer 426 includes a slot 427 at its free endadapted to receive a respective headgear strap in use.

In use, the upper headgear connector 424 is adapted to clip onto theframe 442 (e.g., see FIGS. 40-1 and 40-2). Specifically, intermediateportions of the wire members 428 are received in respective grooves 435of the frame 442, and end portions of the wire members 428 extendthrough respective retaining members 433 with the rigidizers 426providing a shoulder to interlock with respective retaining members 433.FIGS. 40-4 and 40-5 show an upper portion of a retaining member 433 toillustrate the groove 433(1) adapted to receive a respective wire. Asillustrated, the end of the groove 433(1) includes tapered side walls433(2) and drops off towards a rear side 433(3) to position therigidizers 426 into interlocking engagement with the retaining member433.

FIGS. 41-1 to 41-12 illustrate an upper portion of a frame and a clip-onupper headgear connector or rigidizer according to another embodiment ofthe present invention.

As illustrated, the upper portion of the frame 542 includes a retainingmember 533 on each side thereof and a retaining groove 535 along anintermediate portion thereof, which are structured and arranged toretain an upper headgear connector or rigidizer 524.

As best shown in FIGS. 41-5 and 41-12, the upper headgear connector 524includes a pair of elongated arms or rigidizers 526 coupled by aconnecting portion 528. Each rigidizer 526 includes a slot 527 at itsfree end adapted to receive a respective headgear strap in use. Inaddition, the upper headgear connector 524 includes a clip structure 525on each side of the connecting portion 528.

In use, the upper headgear connector 524 is adapted to clip onto theframe 542 (e.g., see FIGS. 41-1 and 41-2). Specifically, the connectingportion 528 is received in the groove 535 of the frame 542, and the clipstructures 525 releasably interlock with respective retaining members533. As best shown in FIGS. 41-3 and 41-4, each retaining member 533provides a cross-bar, and each clip structure 525 provides a v-shapedconfiguration that is adapted to resiliently deflect through thecross-bar and provide a shoulder to releasably interlock with thecross-bar.

FIGS. 42-1 to 42-7 illustrate an alternative embodiment for engaging theupper headgear connector with the frame. As illustrated, each retainingmember 533 provides an open-ended cross-bar, and each clip structure 525provides an elongated arm. In this embodiment, the cross-bar isstructured to resiliently deflect to allow the clip structure 525 toextend through the cross-bar and releasably engage the cross-bar, e.g.,with a friction fit. In addition, the upper headgear connector 524 ofFIGS. 42-1 to 42-7 includes a c-shaped clip structure 529 adapted tointerlock with a tab 549 provided to the frame 542 (see FIGS. 42-1 and42-2).

5.1.6 Grommet Attachment

FIGS. 44 and 45 illustrate an alternative mask arrangement in which theshroud is attached to the frame via a grommet.

For example, as shown in FIG. 44, the frame 740 includes a grommet 745(e.g., constructed of a rubber) and the shroud 720 includes an opening725 adapted to receive the grommet 745 to secure the shroud 720 to theframe 740. As illustrated, the shroud 720 includes elongated upper andlower arms 724, 726 each with a slot 727 at its free end adapted toreceive a respective headgear strap in use.

FIG. 45 illustrates an alternative shroud 820 which includes a singlearm with a slot 827 at each end adapted to receive a respective headgearstrap in use. In addition, the shroud 820 provides an elongated innerslot 825 adapted to receive the grommet 745 of the frame 740. Theelongated slot 825 allows the grommet 745 to be fixed in one of multiplepositions along the length of the slot 825, in contrast to the shroud720 which provides a single fixed position. In an embodiment, the shroud820 may be slidable with respect to the grommet 745 to allow an infinitenumber of positions with respect to the frame 740.

In each embodiment, the grommet 745 (e.g., constructed of a rubber)fixes the shroud in position but the inherent flexibility of the grommetprovides a flexible connection to decouple the shroud from the frame andallow a range of movement between the two components, e.g., like a balljoint or gimbal. Such arrangement helps with fitting and sealing of themask to the patient's face. That is, the flexible connection allows themask to selectively adjust and/or self-fit with the patient's face.

5.2 Cushion to Frame Connection

In FIGS. 1-8, the non-face contacting side of the cushion 1060 isconnected to frame 1040 in a tongue and groove relationship. The tongue1066 (see FIGS. 1C, 1D, and 8) of the cushion 1060 is inserted within agroove 1041 (see FIGS. 1C and 1D) provided along the perimeter of theframe 1040. The tongue and groove relationship may also include alocking lip or sealing lip 1068 (see FIGS. 1C, 1D, and 8) on the cushionthat is adapted to interlock with an undercut bead 1042 (see FIGS. 1Cand 1D) within the frame groove to fixably retain the cushion to theframe.

In the illustrated embodiment, the cushion 1060 also includes one ormore positioning features located around its circumference to assistwith proper alignment of the cushion with the frame 1040. As shown inFIG. 7, the cushion 1060 includes notches and/or protrusions (e.g., twonotches 1067 and one protrusion 1069) adapted to engage withcomplementary features in the frame, e.g., interlocking relationship.

5.2.1 Co-Molding Frame and Cushion

In an embodiment, as shown in FIGS. 27-30, the frame 40 and cushion 44may be co-molded with one another to form a one-piece, integratedcomponent. For example, the frame 40 may be molded of a first materialadapted to interface with the shroud 20 and the cushion 44 may beco-molded onto the frame 40 of a second material adapted to interfacewith patient's face.

In such embodiment, the cushion 44 may be constructed of a relativelysoft elastomeric material (e.g., silicone) for sealing and the frame 40may be constructed of a more rigid material than the cushion 44 (e.g.,polycarbonate, polypropylene) for interfacing with the frame.

Co-molding the frame 40 to the cushion 44 provides a chemical bondwithout necessarily forming a mechanical interlock. As a result, theconnection includes no cracks, a gas tight seal, and clean interface.Moreover, such co-molded connection relaxes tolerances as the moldmaterials are sufficiently flexible to fill in any gaps at the interfacebetween the frame 40 and the cushion 44. Also, the co-moldedframe/cushion provides a reduced part count (reduced cost) andfacilitates assembly/disassembly to the shroud 20.

In an alternative embodiment, as shown in FIG. 33, the frame 40 andcushion 44 may be integrally formed in one piece, e.g., of a siliconematerial. That is, the frame 40 may have the same shape and structure asdescribed above, but be integrally molded of the same material, e.g.,silicone.

In an embodiment, the integrally formed frame 40/cushion 44 may beco-molded to the shroud 20, e.g., constructed of polycarbonate orpolypropylene. For example, the shroud 20 may be constructed of arelatively rigid material (e.g., polycarbonate or polypropylene) and theframe 40/cushion 44 may be co-molded onto the shroud 20 of a relativelysoft elastomeric material (e.g., silicone).

5.3 Vent Arrangement

In FIGS. 1, 1B, 1C, 1D, and 2-5, the vent arrangement 1076 is providedto the frame and includes a plurality of holes 1077 (e.g., 5-100 holes,e.g., 20-50 holes, or about 35 holes) oriented at an angle (e.g., 45°)on the outer surface of the frame so as ensure the exhausted air isdirected away from the patient and preferably their bed partner when thepatient is sleeping. As shown in FIGS. 1C and 1D, each hole 1077 mayinclude a contour or taper along its length. However, it should beappreciated that the vent arrangement may include other suitablearrangements, e.g., different number of holes, hole arrangement,positioning on frame, vent provides part pf interlocking structure withshroud, etc.

FIG. 35-1 illustrates a vent arrangement 276 provided to the frame 240for gas washout. In the illustrated embodiment, the vent arrangement 276is in the form of a vent insert (e.g., elastomeric vent insert) that isadapted to be removably supported within an outlet opening in the frame240. The vent insert may be similar those described in U.S. Pat. Nos.6,561,190, 6,561,191, and 7,207,335, each of which is incorporatedherein by reference in its entirety. However, it should be appreciatedthat the vent arrangement may have other suitable forms (e.g., ventholes in main body, etc.).

FIGS. 37-3, 39-2, and 39-4 illustrate a frame 340 that includes au-shaped slot 302 that receives a u-shaped plug-type vent 305 for gaswashout. As illustrated, the plug-type vent 305 wraps around and underthe opening in the frame 340 for the elbow 370. The plug-type vent 305includes a plurality of tracks or grooves 307 on each side thereof. Inuse, the grooved plug-type vent 305 forms a seal with the slot 302 sothat exhausted air can exit between the slot walls and the grooves 307on the plug-type vent 305. In an embodiment, the port caps 347 may beintegrated or incorporated into the plug-type vent 305 (e.g., integrallyformed in one piece). Further details of such a plug-type ventarrangement are provided in U.S. patent application Ser. No. 12/230,120,filed Aug. 22, 2008, which is incorporated herein by reference in itsentirety. FIGS. 39-2 to 39-6 show the frame 340 with the groovedplug-type vent 305 removed so as to more clearly illustrate the u-shapedslot 302 and auxiliary ports 343 on each side thereof.

Also, it should be appreciated that the vent arrangement may be providedto the elbow. For example, a shown in FIGS. 27-30, the vent arrangement76 is in the form of a vent insert that is adapted to be removablysupported within an outlet opening in the elbow 70. In an embodiment,the vent arrangement 76 includes a base adapted to be supported withinthe outlet opening, one or more grill components or media (e.g., filter,membrane, or other porous material) provided to the base and structuredto diffuse vent flow, and a cover to maintain the grill components/mediawithin the base. Only the cover 77 of the vent arrangement 76 is visiblein FIGS. 27-30.

Exemplary embodiments of such a vent arrangement are disclosed in U.S.patent application Ser. No. 12/230,120, filed Aug. 22, 2008, which isincorporated herein by reference in its entirety.

However, it should be appreciated that the vent arrangement may includeother suitable arrangements, e.g., vent insert with one or more ventholes.

Also, the elbow may provide an alternative venting arrangement to thevent insert. For example, as indicated in dashed lines in FIG. 30, thefirst end portion 74(1) of the elbow 70 (e.g., along the interfacingstructure 75) may include one or more vent holes 276 for gas washout.The one or more holes 276 may be provided to a soft part (e.g., siliconeseal as described below) and/or a hard part (e.g., polycarbonate,polypropylene) of the elbow. The holes 276 may extend around the entireperimeter of the first end portion 74(1) or may extend along one or moreportions of the first end portion 74(1). It is noted that providing ventholes along the entire perimeter of the elbow may help to disperse thevent flow in use. However, other suitable hole arrangements, holenumbers, and/or hole shapes along the first end portion 74(1) and/orother portions of the elbow are possible.

5.4 Ports

In FIGS. 1-5, the base of the frame 1040 includes two ports 1043positioned so that in use, oxygen or other breathable gas can bedelivered close to the patient's nares or pressure monitoring equipmentcan be attached. The ports 1043 may also be used to attach additionalmedical equipment such as pressure or flow sensors. The ports may beselectively closable or sealable by a ports cap.

In an alternative embodiment, as shown in FIGS. 25 and 26, the frame1040 may include a side port 1043.1, e.g., in addition to or as analternative to the ports 1043.

FIGS. 35-1 and 35-2 show a frame 240 that includes an auxiliary port orspigot 243 on an upper portion of the frame, e.g., for supplementaloxygen, measurement device, etc.

In FIGS. 37-1 to 37-3 and 39-1 to 39-6, the frame 340 includes anauxiliary port or spigot 343 on each side thereof, e.g., forsupplemental oxygen, measurement device, etc. Port caps 347 are providedto seal respective ports 343.

6. Interface Seal

In an embodiment, a seal may be provided at the interface between theelbow and the shroud, at the interface between the frame and the shroud,and/or at the interface between the elbow and the frame. For example, aseal (e.g., elastomeric, ring-shaped seal) may be formed separately fromthe modules and attached at the interface (e.g., sandwiched betweenmodules, adhesive, etc.). Alternatively, a seal may be co-molded withone or more of the modules. In an embodiment, a silicone lip seal may beprovided to the frame to seal against the elbow, thereby reducing leak.

In another embodiment, as shown in FIG. 27-30, the interfacing structure75 of the elbow 70 may be constructed of a relatively soft, sealingmaterial (e.g., silicone, which may be co-molded to the harder materialof the elbow) that is structured to provide a seal at the interfacebetween the elbow 70 and the shroud 20. Also, the relatively softinterfacing structure 75 (e.g., silicone) provides a “soft” attachmentto the relatively hard shroud 20 (e.g., polycarbonate, polypropylene)which may allow an interference type fit. As noted above, one or morevent holes may be provided to the softer interfacing structure and/orthe harder elbow.

While the invention has been described in connection with what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the invention. Also, the various embodiments described abovemay be implemented in conjunction with other embodiments, e.g., aspectsof one embodiment may be combined with aspects of another embodiment torealize yet other embodiments. Further, each independent feature orcomponent of any given assembly may constitute an additional embodiment.Furthermore, each individual component of any given assembly, one ormore portions of an individual component of any given assembly, andvarious combinations of components from one or more embodiments mayinclude one or more ornamental design features. In addition, while theinvention has particular application to patients who suffer from OSA, itis to be appreciated that patients who suffer from other illnesses(e.g., congestive heart failure, diabetes, morbid obesity, stroke,bariatric surgery, etc.) can derive benefit from the above teachings.Moreover, the above teachings have applicability with patients andnon-patients alike in non-medical applications.

1-20. (canceled)
 21. A mask system to provide positive air pressuretherapy to a patient, the mask system comprising: a cushion modulecomprising: a frame having an interior surface forming a breathingchamber, the frame including a circular frame opening positioned toreceive a supply of air at positive pressure, wherein the frame includesa cylindrical collar surrounding the frame opening and extending awayfrom an exterior surface of the frame, the collar having a longitudinalaxis, and the collar having a cylindrical surface with an axis that iscoincident with the longitudinal axis of the collar, wherein the collarincludes at least one radial protrusion extending from the cylindricalsurface, the at least one radial protrusion having an annular orpart-annular shape and having a curvature centered about thelongitudinal axis of the collar, wherein the frame, including the collarand the at least one radial protrusion, is constructed frompolycarbonate, and a cushion constructed of silicone, the polycarbonateof the frame being harder than the silicone of the cushion, the framebeing more rigid than the cushion, the cushion configured to sealagainst the patient's face in use to enable the supply of air atpositive pressure to be delivered to the patient, the cushion isconstructed to engage the patient's face along a nasal bridge region, acheek region, and a lower lip/chin region of the patient's face when inuse, wherein the cushion and the frame are joined to form a one-piece,integrated component; an elbow configured to receive the supply of airat positive pressure and deliver the supply of air at positive pressureto the breathing chamber, the elbow having an anti-asphyxia valve; ashroud without a forehead support, the shroud configured to removablyconnect to the frame of the cushion module, wherein the shroud includesa circular elbow opening that accommodates the elbow, wherein the shroudincludes a rear surface at least partly covering the exterior surface ofthe frame, the shroud having a plurality of part-annular snap connectionportions circumferentially spaced from one another and centered about alongitudinal axis of the elbow opening, the snap connection portionsbeing positioned rearward of the elbow opening of the shroud, whereinthe shroud, including the snap connection portions, is constructed frompolycarbonate, the polycarbonate of the shroud being harder than thesilicone of the cushion, and the shroud being more rigid than thecushion; headgear configured to connect to the shroud to maintain thecushion module in position on the patient's head in use, the headgearcomprising a pair of upper straps, each of the pair of upper strapsconfigured to be positioned on a corresponding lateral side of thepatient's head in use, and a pair of lower straps, each of the pair oflower straps configured to be positioned on a corresponding lateral sideof the patient's head in use; and a vent arrangement having a pluralityof holes for gas washout from the breathing chamber to atmosphere,wherein: the shroud includes a pair of upper headgear connectors and apair of lower headgear connectors, said pair of upper headgearconnectors structured to connect to said headgear, and said pair oflower headgear connectors structured to connect to said headgear viaclips, each of the pair of upper headgear connectors comprises anelongated arm to direct a corresponding one of the pair of upper strapsaway from the patient's corresponding eye, each elongated arm beingshaped to follow contours of the patient's face and avoid the patient'sline of sight in use, a portion of each elongated arm is enveloped by afabric sleeve, each elongated arm is constructed of a flexible materialthat is different than the polycarbonate of the shroud, each elongatedarm is connected to the shroud, each elongated arm is configured to bepositioned inferior to the patient's corresponding eye in use and isconfigured to direct a corresponding one of the pair of upper strapssuperior to the patient's corresponding ear in use, each of the pair oflower headgear connectors is configured to direct a corresponding one ofthe pair of lower straps inferior to the patient's corresponding ear inuse to releasably connect the shroud to the cushion module, the at leastone radial protrusion and the snap connection portions are structured toresiliently deflect relative to one another in a radial directionrelative to the longitudinal axis of the collar to form a removablesnap-fit connection between the at least one radial protrusion and thesnap connection portions by moving the cushion module and the shroudtowards one another along the longitudinal axis of the collar, when thecollar and the snap connection portions are joined to form the removablesnap-fit connection, the cushion module and the shroud are stabilizedagainst rotation relative to one another, the elbow is directly attachedvia a snap fit to the shroud at the elbow opening, and the elbow isrotatable 360° relative to the shroud.
 22. The mask system of claim 21,wherein the frame includes a rearwardly extending portion that isconstructed of the polycarbonate of the frame, the rearwardly extendingportion extending rearward from the collar and terminating in an edgehaving a substantially triangular shape, and wherein the cushion isjoined to the frame about the edge.
 23. The mask system of claim 22,wherein the rearwardly extending portion includes the interior surfaceof the frame that forms the breathing chamber.
 24. The mask system ofclaim 21, wherein the shroud includes an annular structure surroundingthe elbow opening, the annular structure being constructed of thepolycarbonate of the shroud, wherein the elbow includes an annular tube,the annular structure of the shroud being structured to engage theannular tube of the elbow when the elbow is connected to the shroud, andwherein when the frame, the shroud, and the elbow are assembledtogether, the annular structure of the shroud, the annular tube of theelbow, and the collar of the frame are nested together such that a planeperpendicular to the longitudinal axis of the collar intersects each ofthe annular structure of the shroud, the annular tube of the elbow, andthe collar.
 25. The mask system of claim 21, wherein a portion of theshroud surrounding the elbow opening, a portion of the elbow thatengages the shroud at the elbow opening, and the collar of the frame arenested together such that a plane perpendicular to the longitudinal axisof the collar intersects each of the shroud, the elbow, and the collarwhen the frame, the shroud, and the elbow are assembled together. 26.The mask system of claim 21, wherein the collar comprises a front endpositioned to face away from the patient in use, and wherein when theframe and the shroud are assembled together, the front end of the collaris positioned rearward of the rear surface of the shroud.
 27. The masksystem of claim 21, wherein: the frame includes a rearwardly extendingportion that is constructed of the polycarbonate of the frame, therearwardly extending portion extending rearward from the collar andterminating in an edge having a substantially triangular shape, thecushion is joined to the frame about the edge, the rearwardly extendingportion includes the interior surface of the frame that forms thebreathing chamber, a portion of the shroud surrounding the elbowopening, a portion of the elbow that engages the shroud at the elbowopening, and the collar of the frame are nested together such that aplane perpendicular to the longitudinal axis of the collar intersectseach of the shroud, the elbow, and the collar when the frame, theshroud, and the elbow are assembled together, the collar comprises afront end positioned to face away from the patient in use, and when theframe and the shroud are assembled together, the front end of the collaris positioned rearward of the rear surface of the shroud.
 28. A masksystem to provide positive air pressure therapy to a patient, the masksystem comprising: a cushion module comprising: a frame having aninterior surface forming a breathing chamber, the frame including acircular frame opening positioned to receive a supply of air at positivepressure, wherein the frame includes a cylindrical collar surroundingthe frame opening and extending away from an exterior surface of theframe, the collar having a longitudinal axis, and the collar having acylindrical surface with an axis that is coincident with thelongitudinal axis of the collar, wherein the collar includes a firstradial protrusion and a second radial protrusion extending from thecylindrical surface, each of the first radial protrusion and the secondradial protrusion having a part-annular shape and having a curvaturecentered about the longitudinal axis of the collar, wherein the frame,including the collar and each of the first radial protrusion and thesecond radial protrusion, is constructed from a first material, and acushion constructed of an elastomeric material that is a differentmaterial from the first material, the first material of the frame beingharder than the elastomeric material of the cushion, the frame beingmore rigid than the cushion, the cushion configured to seal against thepatient's face in use to enable the supply of air at positive pressureto be delivered to at least the patient's nose, wherein the cushion andthe frame are joined to form a one-piece, integrated component; an elbowconfigured to receive the supply of air at positive pressure and deliverthe supply of air at positive pressure to the breathing chamber; ashroud configured to removably connect to the frame of the cushionmodule, wherein the shroud includes a circular elbow opening thataccommodates the elbow, wherein the shroud includes a rear surface atleast partly covering the exterior surface of the frame, the shroudhaving a first part-annular snap finger and a second part-annular snapfinger circumferentially spaced from one another and centered about alongitudinal axis of the elbow opening, the first part-annular snapfinger and the second part-annular snap finger being positioned rearwardof the elbow opening of the shroud, wherein the shroud, including thefirst part-annular snap finger and the second part-annular snap finger,is constructed from a second material, the second material of the shroudbeing harder than the elastomeric material of the cushion, and theshroud being more rigid than the cushion; headgear configured to connectto the shroud to maintain the cushion module in position on thepatient's head in use; and a vent arrangement having a plurality ofholes for gas washout from the breathing chamber to atmosphere, whereinthe shroud includes a pair of upper headgear connectors and a pair oflower headgear connectors, said pair of upper headgear connectorsstructured to connect to said headgear, and said pair of lower headgearconnectors structured to connect to said headgear via clips, wherein, toreleasably connect the shroud to the cushion module, each of the firstradial protrusion and the second radial protrusion and a correspondingone of the first part-annular snap finger and the second part-annularsnap finger are structured to resiliently deflect relative to oneanother in a radial direction relative to the longitudinal axis of thecollar to form a removable snap-fit connection between the first radialprotrusion and the second radial protrusion and the first part-annularsnap finger and the second part-annular snap finger by moving thecushion module and the shroud towards one another along the longitudinalaxis of the collar, and wherein when the first radial protrusion and thesecond radial protrusion and the first part-annular snap finger and thesecond part-annular snap finger are joined to form the removablesnap-fit connection, the cushion module and the shroud are stabilizedagainst rotation relative to one another.
 29. The mask system of claim28, wherein: the cylindrical surface is on an exterior of the collar,the first radial protrusion and the second radial protrusion are spacedcircumferentially about the cylindrical surface, the first radialprotrusion and the second radial protrusion and the first part-annularsnap finger and the second part-annular snap finger are configured toform the removable snap-fit connection between a front end of thecylindrical surface and a rear end of the cylindrical surface, thecushion is constructed to engage the patient's face along a nasal bridgeregion, a cheek region, and an upper lip region of the patient's facewhen in use, the elastomeric material of the cushion is silicone, theshroud does not include a forehead support, the first material ispolycarbonate, the second material is polycarbonate, the cushion and theframe are joined by a chemical bond, the elbow is directly attached viaa snap-fit to the shroud at the elbow opening, the elbow is rotatable360° relative to the shroud, the headgear comprises a pair of upperstraps, each of the pair of upper straps configured to be positioned ona corresponding lateral side of the patient's head in use, and a pair oflower straps, each of the pair of lower straps configured to bepositioned on a corresponding lateral side of the patient's head in use,each of the pair of upper headgear connectors comprises an elongated armto direct a corresponding one of the pair of upper straps away from thepatient's corresponding eye, each elongated arm being shaped to followcontours of the patient's face and avoid the patient's line of sight inuse, each elongated arm has an inner surface including a cheek pad, eachelongated arm is constructed of a flexible material that is differentthan the second material of the shroud, the elongated arms are coupledto one another via a connecting portion that is connected to the shroud,each elongated arm is configured to be positioned inferior to thepatient's corresponding eye in use and is configured to direct acorresponding one of the pair of upper straps superior to the patient'scorresponding ear in use, each of the pair of lower headgear connectorsis configured to direct a corresponding one of the pair of lower strapsinferior to the patient's corresponding ear in use, and the mask systemfurther includes a seal at an interface between the elbow and the frame.30. The mask system of claim 28, wherein: the cushion is constructed toengage the patient's face along a nasal bridge region, a cheek region,and a lower lip/chin region of the patient's face when in use, theelastomeric material of the cushion is silicone, the cushion and theframe are constructed and arranged to be in an interlocking relationshipwith one another, the first material is polycarbonate, the secondmaterial is polycarbonate, said headgear comprises hook and loopmaterial, the shroud further comprises a forehead support, the elbow isdirectly attached to the shroud at the elbow opening, the elbow includesan anti-asphyxia valve, the vent arrangement comprises a protruding ventarrangement that protrudes from the frame, the protruding ventarrangement including a vent-wall having the plurality of holes, thevent-wall being spaced from the frame by a lower wall and two lateralside walls of the protruding vent arrangement, and the protruding ventarrangement positioned above the frame opening, the first radialprotrusion and the second radial protrusion are spaced circumferentiallyabout the frame opening, the first radial protrusion and the secondradial protrusion and the first part-annular snap finger and the secondpart-annular snap finger are configured to form the removable snap-fitconnection between a front end of the cylindrical surface and a rear endof the cylindrical surface relative to the patient in use, the headgearcomprises a pair of upper straps, each of the pair of upper strapsconfigured to be positioned on a corresponding lateral side of thepatient's head in use, and a pair of lower straps, each of the pair oflower straps configured to be positioned on a corresponding lateral sideof the patient's head in use, each of the pair of upper headgearconnectors is configured to direct a corresponding one of the pair ofupper straps superior to the patient's corresponding ear in use, each ofthe pair of lower headgear connectors is configured to direct acorresponding one of the pair of lower straps inferior to the patient'scorresponding ear in use, the part-annular shape of each of the firstpart-annular snap finger and the second part-annular snap finger has acurvature that is centered on the longitudinal axis of the collar, aregion of the cushion positioned to engage the nasal bridge region ofthe patient is configured to allow increased movement compared toanother region of the cushion that is adapted to seal with anotherregion of the patient's face, and the mask system being constructed sothat the snap-fit connection is established when a force is applied tomove the shroud and cushion module toward one another along thelongitudinal axis until a ramped rear end of each of the firstpart-annular snap finger and the second part-annular snap fingerinitially contacts a front end of a corresponding one of the firstradial protrusion and the second radial protrusion on the collar,whereupon further application of the force causes each of the firstpart-annular snap finger and the second part-annular snap finger to rideover a corresponding one of the first radial protrusion and the secondradial protrusion and therefore resiliently deflect in a first radialdirection, and upon further movement towards one another, each of thefirst part-annular snap finger and the second part-annular snap fingerresiliently moves in a second radial direction, opposite the firstradial direction, and engages a rear end of a corresponding one of thefirst radial protrusion and the second radial protrusion to snap each ofthe first part-annular snap finger and the second part-annular snapfinger into place, thereby removably connecting the shroud and thecushion module.
 31. The mask system of claim 28, wherein: the firstradial protrusion and the second radial protrusion are spacedcircumferentially about the cylindrical surface, the cushion isconstructed to engage the patient's face along a nasal bridge region, acheek region, and an upper lip region of the patient's face when in use,the cushion and the frame are constructed and arranged to be in aninterlocking relationship with one another, the elastomeric material ofthe cushion is silicone, said headgear comprises hook and loop material,the shroud includes a forehead support, the first material ispolycarbonate, the second material is polycarbonate, the elbow isdirectly attached to the shroud at the elbow opening, the elbow isrotatable 360° relative to the shroud, the headgear comprises a pair ofupper straps, each of the pair of upper straps configured to bepositioned on a corresponding lateral side of the patient's head in use,and a pair of lower straps, each of the pair of lower straps configuredto be positioned on a corresponding lateral side of the patient's headin use, each of the pair of upper headgear connectors is configured todirect a corresponding one of the pair of upper straps superior to thepatient's corresponding ear in use, each of the pair of lower headgearconnectors is configured to direct a corresponding one of the pair oflower straps inferior to the patient's corresponding ear in use, thepart-annular shape of each of the first part-annular snap finger and thesecond part-annular snap finger has a curvature that is centered on thelongitudinal axis of the collar, a region of the cushion positioned toengage the nasal bridge region of the patient is configured to allowincreased movement compared to another region of the cushion that isadapted to seal with another region of the patient's face, and the masksystem being constructed so that the snap-fit connection is establishedwhen a force is applied to move the shroud and cushion module toward oneanother along the longitudinal axis until a ramped rear end of each ofthe first part-annular snap finger and the second part-annular snapfinger initially contacts a front end of a corresponding one of thefirst radial protrusion and the second radial protrusion on the collar,whereupon further application of the force causes each of the firstpart-annular snap finger and the second part-annular snap finger to rideover a corresponding one of the first radial protrusion and the secondradial protrusion and therefore resiliently deflect in a first radialdirection, and upon further movement towards one another, each of thefirst part-annular snap finger and the second part-annular snap fingerresiliently moves in a second radial direction, opposite the firstradial direction, and engages a rear end of a corresponding one of thefirst radial protrusion and the second radial protrusion to snap each ofthe first part-annular snap finger and the second part-annular snapfinger into place, thereby removably connecting the shroud and thecushion module.
 32. The mask system of claim 31, further comprising atleast one tab and recess arrangement positioned circumferentiallybetween mating ones of the first part-annular snap finger and the secondpart-annular snap finger and the first radial protrusion and the secondradial protrusion, the tab and recess arrangement resisting rotation ofthe collar relative to the shroud upon establishing the snap-fitconnection between the shroud and the cushion module.